If the devices are currently in another group you can move devices between groups fairly easily. Enter that group in IC2 and go to the bottom of the device list. You should see an edit button, click on that to show check boxes.

Click the check boxes for any devices that you’d like to move. Click the Actions button. Now click the Move to… text to select the IC2 Group that you would like to move the device to. If the group you’d like to move any devices to is in another Organization the device will have to be removed from the existing IC2 account and added to the new one.

The process for removing devices is almost the same but rather then clicking the *Move to… text, you’ll need to click the Remove… text.